What is SQL Injection?

SQL Injection is a security vulnerability that allows an attacker to manipulate the SQL queries used by an application. It occurs when user input is improperly handled and incorporated directly into SQL queries, allowing the attacker to execute arbitrary SQL commands. This can lead to various malicious activities, such as retrieving, modifying, or deleting data from the database, bypassing authentication, and even gaining administrative privileges.

Example of SQL Injection:

A vulnerable query might look like this:

$query = "SELECT * FROM users WHERE username = '$username' AND password = '$password'";

If the attacker enters ' OR '1'='1' for both the username and password fields, the query becomes:

SELECT * FROM users WHERE username = '' OR '1'='1' AND password = '' OR '1'='1';

This will always return true, potentially allowing unauthorized access to the system.

How to Prevent SQL Injection:

1. Prepared Statements and Parameterized Queries: Use prepared statements with parameterized queries to ensure that user input is not directly inserted into SQL queries.
2. Input Validation: Sanitize and validate all user inputs to ensure that only expected data is passed to the database.
3. Escaping Input: Properly escape any special characters in user inputs.
4. Use ORM (Object-Relational Mapping) Tools: These tools handle SQL queries in a more secure way, reducing the risk of injection.
5. Limit Database Privileges: Restrict database user permissions to minimize the impact of a successful attack.

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About Ajay

Ajay Singh is a professional programmer and loves to explore anything related to computer.